Obama homed in on Trump's economic plans and domestic policies without mentioning the mogul by name.

"If we turn against each other based on divisions of race or religion, if we fall for a bunch of 'okey-doke,' just because it sounds funny or the tweets are provocative, then we're not going to build on the progress we started," Obama said. "If we get cynical and just vote our fears, or if we don't vote at all, we won't build on the progress that we started."

The trip marks the start of what will be Obama's final mission: working to keep a Democrat in the White House once he leaves it in January. He has yet to endorse a Democratic candidate as the primary is still ongoing, although has made clear his preference for the near-certain nominee, Hillary Clinton, who served as his first secretary of state.

Obama has landed punches on Trump throughout the past few months, but his Wednesday speech was the first geared specifically toward the upcoming election.

"If what you care about in this election is your pocketbook, if what you're concerned about is who will look out for the interests of working people and grow the middle class, if that's what you're concerned about — the economy — the debate is not even close," Obama said.

He specifically railed on Trump's proposal to dismantle the Dodd-Frank law, asking the audience if they had "forgotten what just happened eight years ago" and calling it "crazy."

"I don't care whether you're a Republican or a Democrat or an independent," he said. "Why would you do that? Less oversight on Wall Street would only make another crisis more likely. How can you say you're for the middle class and then you want to tear down these rules?"

"Don't think that actually this agenda is going to help you," he continued. "It's not designed to help you."

AP Photo/Pablo Martinez Monsivais

He used some of his most critical language of the election cycle to push back against ideas and proposals he said are promoted by the Republican Party — and Trump.

"In today's economy, we can't put up walls around America," he said. "We're not going to round up 11 million people, we're not going to put technology back in the box, we're not going to rip away hard-earned rights for women and minorities and Americans with disabilities."

"These are permanent fixtures in our economy, and rolling them back will not help folks in Elkhart or anywhere else," he continued, later adding that a Republican administration would lead to an economic disaster.

He went on:

Look, I'm just being blunt with you — by telling hardworking, middle-class families that the reason they're getting squeezed is because of some moochers at the bottom of the income ladder, because of minorities, or because of immigrants, or because of public employees, or because of feminists — because of poor folks who aren't willing to work, they've been able to promote policies that protect powerful special interests and those who are at the very top of the economic pyramid. That's just the truth.

AP Photo/Pablo Martinez Monsivais

A White House source told CNN that Obama can't wait to "get people fired up" once the Democratic Party selects its presidential nominee. The source said that Obama expects to "explode onto the scene" afterward and "knows his power" with the Democratic base.

Obama delivered the speech at Concord Community High School, which was the site of his first major trip as president in 2009. He highlighted how the unemployment rate in Elkhart dropped dramatically from the Great Recession, when it peaked at 19.6%, to today, where it sits at 4.1%, according to the US Office of Management and Budget.

Republican National Committee spokesman Michael Short said in a statement following the speech that the president was "trying to convince voters his record of weak growth, stagnant wages and a shrinking middle class is really a success story."